How severe is CVE-2020-8599?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2020-8599 known to be exploited?

Yes. CVE-2020-8599 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.

Vulnerability in Trend Micro Officescan, Apex One

CVE-2020-8599

Trend Micro Apex One (2019) and OfficeScan XG server contain a vulnerable EXE file that could allow a remote attacker to write arbitrary data to an arbitrary path on affected installations and bypass ROOT login. Authentication is not required to exploit this vulnerability.

Published 2020-03-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.119 (96.1th percentile), scored 2026-10-18.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 96th percentile — 96.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.119 · newest: 0.119 · change: 0.000

Affected products

Trend Micro Officescan, Apex One — versions OfficeScan XG (12.0), Apex One 2019 (14.0)
Trendmicro Apex One — versions 2019
Trendmicro Officescan — versions xg

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-05-03.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

success.trendmicro.com/solution/000245571 (Patch, Broken Link, Vendor Advisory)
success.trendmicro.com/jp/solution/000244253 (Patch, Broken Link, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2020-8599?: CVE-2020-8599 is a critical-severity vulnerability in Trend Micro Officescan, Apex One. CVSS score: 9.8/10. Published 2020-03-18.
How severe is CVE-2020-8599?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2020-8599 known to be exploited?: Yes. CVE-2020-8599 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.